Ditch the ORY and get some duals.

 

yes, you could get a piece of 1/4 drawn rod, and weld it to the y pipe right near the driver side tunnel, then push a piece of heater hose over the rod, this would stop the banging. also try a big strap wrench this will allow you to turn the pipes a bit if needed, you want at least a hand widths all over, so put your hand between the y and the body before you tighen the clamps, any banging can lead to knock retard, and all around being pissed off.

 

I had a little bang with my Kooks catted y under hard acceleration and tire spin. Took it to a muffler shop and they welded a bracket onto the kooks y that fit into the rubber bracket that is used by the stock y. It banged less, but after a couple hard knocks on speed bumps, sidewalks, burnouts, and **** like that, I don't have any more problems.

The Kooks y's are pretty good, but not perfect. Mine actually came a little damaged and required an anvil and hammer to get one of the openings rights.